More OEM Minutia, Carpet Backings Options

[StarBear]

@wonkipop
@jeffbowlsby
@van b
@big len
In the midst of finally replacing a few key pieces of my original carpeting. Noticed something somewhat strange (see pics). The backing on the driver’s side (on right) is lighter and kind of light, stiff pvc or something. Stamped with “TSB”. Passenger side backing is black and much more rubbery; not stiff at all. Same situation with the NOS pieces I’m preparing to put in and the NOS passenger mat already in (not in pics).

Any experience, insight, or history on this. These are known (mine) original pieces.
As promised, truly minutia.
Thanks!

Backs of Originals:


Backs of New NOS:

[wonkipop]

@StarBear

non AG (basement bin model) brown interior in my car?
you can see how i didn't get the brown bits on the doors or the cushion.
as i say i can only vouch for it since 89, but again i doubt the original owner would have mucked with it too much. i know for instance the steering wheel is the one that has been on it since delivery new. the original owner had the dealer install it. was some kind of standard kit alternative the dealers had. gut clearance option that USA dealers had ready to go. (IMG:style_emoticons/default/beer.gif)

i guess thats one for @JeffBowlsby . mr b is bound to know the answer.